1. Field of the Invention
The invention relates to a power module, and in particular, relates to a method of packaging the power module.
2. Description of the Related Art
Power converters have been widely utilized in commercialized power management category. For example, DC/DC conversion, or providing constant current flow. FIG. 1A shows a diagram of a traditional power converter 100. The power converter 100 comprises a pulse width modulating controller (PWM controller), NMOSFETs Q1 and Q2, an inductor L1, and a capacitor C1. The PWM controller controls ON/OFF state of the NMOSFETs Q1 and Q2 by providing a first control signal Hdry to a gate of the NMOSFET Q1 and providing a second control signal Ldry to a gate of the NMOSFET Q2, wherein the first control signal Hdry is a periodical signal, and the second control signal Ldry is complemetary to the first control signal Hdrv. When the first control signal Hdry is HIGH and the second control signal Ldry is LOW, the NMOSFET Q1 is ON and the NMOSFET Q2 is OFF, and the inductor L1 and the capacitor C1 are charged through the NMOSFET Q1 by an input voltage VDD. When the first control signal Hdry is LOW and the second control signal Ldry is HIGH, the NMOSFET Q1 is OFF and the NMOSFET Q2 is ON, and the inductor L1 and the capacitor C1 are discharged through the NMOSFET Q2 toward a reference voltage level GND, The power converter 100 thus provides a constant voltage output Vload to a load Rload.
With advancement of VLSI fabrication technology, cost, footprint and design flexibility of power modules have become crucial. Modulized packaging of power modules have gained a significant advantage over traditional packaging. For example, as shown in FIG. 1B, a power converter 200 integrates a PWM controller, and NMOSFETs Q1 and Q2 into a multi-chip module (MCM) 20. FIG. 1C shows another power converter 300, which integrates NMOSFETs Q1 and Q2 into an independent package structure 30. However, the power modules mentioned above are inconvenient when being incorporated with different PWM controllers and still have room for improvement.